This invention relates to load handling devices and more particularly concerns a rotatable bed and roller assembly for such devices.
Load handling devices such as lift cranes and the like are commonly provided with a rotatable bed on which the upper works of the crane including the boom and hoist drums are located. In large, heavy-duty lift cranes a counterweight of considerable mass is carried on the rear end of the rotatable bed opposite the boom. It is, of course, necessary for the rotatable bed to support not only the counterweight but also the pay load being lifted by the crane. In addition to the load supporting rollers, the rotatable bed must also be provided with hook rollers to counteract the tipping moment imparted to the rotatable bed by the payload during lifting and by the counterweight at other times.
It is the primary aim of the present invention to provide an improved heavy-duty rotatable bed and roller assembly for a lift crane or the like.
A more detailed object is to provide a novel hook roller assembly which permits adjustment and removal of a plurality of hook rollers as a unit.
It is also an object of the invention to provide a front roller assembly wherein the front load bearing rollers and the front hook rollers are mounted on a common sub-frame secured to the rotatable bed of a lift crane or the like.